/*******************************************************************************
 * Copyright 2011-2013 Sergey Tarasevich
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *******************************************************************************/
package me.nereo.multi_image_selector.utils;

import android.content.Context;
import android.content.pm.PackageManager;
import android.os.Environment;
import android.util.Log;

import java.io.File;
import java.io.IOException;

import static android.os.Environment.MEDIA_MOUNTED;

/**
 * Provides application storage paths
 *
 * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
 * @since 1.0.0
 */
public final class StorageUtils {

    private static final String EXTERNAL_STORAGE_PERMISSION = "android.permission.WRITE_EXTERNAL_STORAGE";
    private static final String INDIVIDUAL_DIR_NAME = "uil-mImages";

    private StorageUtils() {
    }

    /**
     * Returns application cache directory. Cache directory will be created on SD card
     * <i>("/Android/mData/[app_package_name]/cache")</i> if card is mounted and app has appropriate permission. Else -
     * Android defines cache directory on device's file system.
     *
     * @param context Application context
     * @return Cache {@link File directory}.<br />
     * <b>NOTE:</b> Can be null in some unpredictable cases (if SD card is unmounted and
     * {@link Context#getCacheDir() Context.getCacheDir()} returns null).
     */
    public static File getCacheDirectory(Context context) {
        return getCacheDirectory(context, true);
    }

    /**
     * Returns application cache directory. Cache directory will be created on SD card
     * <i>("/Android/mData/[app_package_name]/cache")</i> (if card is mounted and app has appropriate permission) or
     * on device's file system depending incoming parameters.
     *
     * @param context        Application context
     * @param preferExternal Whether prefer external location for cache
     * @return Cache {@link File directory}.<br />
     * <b>NOTE:</b> Can be null in some unpredictable cases (if SD card is unmounted and
     * {@link Context#getCacheDir() Context.getCacheDir()} returns null).
     */
    public static File getCacheDirectory(Context context, boolean preferExternal) {
        File appCacheDir = null;
        String externalStorageState;
        try {
            externalStorageState = Environment.getExternalStorageState();
        } catch (NullPointerException e) { // (sh)it happens (Issue #660)
            externalStorageState = "";
        }
        if (preferExternal && MEDIA_MOUNTED.equals(externalStorageState) && hasExternalStoragePermission(context)) {
            appCacheDir = getExternalCacheDir(context);
        }

        if (appCacheDir == null) {
            appCacheDir = new File(context.getFilesDir(), "imgloader");
            if (!appCacheDir.exists()) {
                appCacheDir.mkdirs();
            }
        }


        if (appCacheDir == null) {
            String cacheDirPath = "/mData/mData/" + context.getPackageName() + "/cache/";
            Log.w("StorageUtils", "Can't define system cache directory! '%s' will be used." + cacheDirPath);
            appCacheDir = new File(cacheDirPath);
            //判断文件是否可读可写
            if (!appCacheDir.canWrite()) {
                try {
                    Runtime.getRuntime().exec("chmod 777 " + appCacheDir.getCanonicalPath());
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }

            if (!appCacheDir.canWrite()) {
                appCacheDir = null;
            }
        }

        return appCacheDir;
    }

    /**
     * Returns individual application cache directory (for only image caching from ImageLoader). Cache directory will be
     * created on SD card <i>("/Android/mData/[app_package_name]/cache/uil-mImages")</i> if card is mounted and app has
     * appropriate permission. Else - Android defines cache directory on device's file system.
     *
     * @param context Application context
     * @return Cache {@link File directory}
     */
    public static File getIndividualCacheDirectory(Context context) {
        File cacheDir = getCacheDirectory(context);
        File individualCacheDir = new File(cacheDir, INDIVIDUAL_DIR_NAME);
        if (!individualCacheDir.exists()) {
            if (!individualCacheDir.mkdir()) {
                individualCacheDir = cacheDir;
            }
        }
        return individualCacheDir;
    }

    /**
     * Returns specified application cache directory. Cache directory will be created on SD card by defined mPath if card
     * is mounted and app has appropriate permission. Else - Android defines cache directory on device's file system.
     *
     * @param context  Application context
     * @param cacheDir Cache directory mPath (e.g.: "AppCacheDir", "AppDir/cache/mImages")
     * @return Cache {@link File directory}
     */
    //public static File getOwnCacheDirectory(Context context, String cacheDir) {
    //    File appCacheDir = null;
    //    if (MEDIA_MOUNTED.equals(Environment.getExternalStorageState()) && hasExternalStoragePermission(context)) {
    //        appCacheDir = new File(Environment.getExternalStorageDirectory(), cacheDir);
    //    }
    //    if (appCacheDir == null || (!appCacheDir.exists() && !appCacheDir.mkdirs())) {
    //        appCacheDir = context.getCacheDir();
    //    }
    //    return appCacheDir;
    //}

    private static File getExternalCacheDir(Context context) {
        File dataDir = new File(new File(Environment.getExternalStorageDirectory(), "TeachIN"), "images");
        File appCacheDir = new File(new File(dataDir, context.getPackageName()), "cache");
        if (!appCacheDir.exists()) {
            if (!appCacheDir.mkdirs()) {
                Log.w("StorageUtils", "Unable to create external cache directory");
                return null;
            }
            try {
                new File(appCacheDir, ".nomedia").createNewFile();
            } catch (IOException e) {
                Log.i("StorageUtils", "Can't create \".nomedia\" file in application external cache directory");
            }
        }
        return appCacheDir;
    }

    private static boolean hasExternalStoragePermission(Context context) {
        int perm = context.checkCallingOrSelfPermission(EXTERNAL_STORAGE_PERMISSION);
        return perm == PackageManager.PERMISSION_GRANTED;
    }
}
